We dont seem to need the wireguard key anymore, we generate a key on
startup based on the new library and the users fetch it from /key.
Clean up app.go and update docs
This commit changes the way CLI and grpc-gateway communicates with the
gRPC backend to socket, instead of localhost. Unauthenticated access now
goes on the socket, while the network interface will require API key (in
the future).
Kristoffer Dalby